Electrically-operated adding-machine.



N6. 890,960. PATENTED JUNE 16, 1908. R. L. BURD.

EL'EGTRIGALLY OPERATED ADDING MACHINE.

APPLICATION FILED FEB. 7, 1907.

4 SHEETS-SHEET 1.

Nb. 8901960. PATENTED JUNE 16, 1908.

R. L. BURD.

ELEGTRIGALLY OPERATED ADDING MACHINE.

APPLIOATION IXLBD FEB. 7, 1907.

4 SHEETS-SHEET 2.

spoi W No. 890,960. PATENTED JUNE 16, 1.908.

R.L.BURD.- BLEGTRIGALLY QPERATBD ADDING MACHINE.

PPLIGATION FILED FEE. 7, 1 07. A 9 4 SHEETS-SHEET 3.

ms. 890,960. PATENTEDJUNElG, 1908..

R.L.BURD. I

ELEGTRIGALLY OPERATED ADDING MAGHINE.

APPLIOATION FILED IEB- 7. 1907.

4 SHEETS-SHEET 4.

4% JUCTYZE UNITED STATES PATENT OFFICE.

ROY L. BURD, OFDETROIT; MICHIGAN, ASSIGNOR TO BURROUGHS ADDING MACHINECOM- PANY, OF DETROIT, MICHIGAN, A HORPORATION OF MICHIGAN.

ELEGTBIGALLY-OPERATEI ADDIISIG-MACHINE.

Specification of Letters Patent,

Patented June 16, 1908.

application filed February 7, 1907. Serial l lo. 356,226.

To all; whom it may concern:

Beiit known that LROY L. BURD, a citizen of the .United States, residingat Detroit,

Waynecounty, Michigan, have invented cer' tam new and useful Imrovements in Electricall -Qperated Adding-Machines, of which rent hasbeen turned on so that with an alternati'ng currentv motor no'difiicultywill be en- I countered on account of oor starting torque. "Thus bypreventing elf ctive manipulation of the starting key until the motorhas at;

tained a predetermined speed the motor cannot be deleteriously affectedb prematurely placing a load upon it. As t ealternating current motor,oes not develop anything like full power'short of attaining practically.full speed it is preferable to prevent effective operation by anelectric motor and aving manipulation of the starting key until thispoint is reached.

. In the present-embodiment of the inven' tion the armature shaft of themotor carries a centrifugal-switch normally closed to afford a path ofleast resistance for the current which "traverses the field magnets. Asfull speed is reached in rotation of the. armature shaftcentrifugal'force operates to automatically open the switch. hereuponthe current is shunted through an electromagnet whose ar for thestarting mature constitutes alock mechanism; I 1

In the accompanying drawings which illustrate the invention ina-preferred form Figure 1 represents partly in right-side elevation andpartly in section an adding machine of the wcll-known Burroughs typeequip ;-ed for automatic controlling devices of the character aboveindicated; Fig. 2 represents in leftside elevation part of theconnections hetwecn. the motor and the adding machine; Fig. 3 representsin vertical section certain clutch and detent devices which control thedriving connection between the motor and the adding machine;-Fig. trepresents a transverse section of thedriving connections between themotor and the adding machine;

5 represents a transverse section of the p motor to ether with a rilit-s de elevation of theassociated starter loo 5 Fig. 6 represents,

machine dependent upon the.

an elevation of the centrifugal switch; Fig. 7 is a diagram of circuitstogether with an elevation of the starter lock, and Fig. 8 is across-section on line 8 of Fig. 6.

While the-invention is preferably shown as applied to the well-knownBurroughs adding and listing machine it is to be understood that it maybe equally well applied to other t pes or" such machines. For thedetails of t. e particular-type here chosen for purposes of illustrationreference may be had to the William 55. Burroughs patents Nos. 504,963and 505,078 of June 12, 189-3. For the purposes of the presentspecification it will suffice to merely refer to a few of the familiarparts of this Burroughs machine The reference numeral 800 designates theusual stub drive shaft to which the detachable handle is appliedwhen themachine is operated by hand, this shaft carrying a hull stroke sector311. The latter is cranked through the medium of a distensible link1851;} to an oscillatory drive. shaft 100; The electric motor issuspended beneath the adding machine and is adapted to him said shaft100 against the stress of springs 180 which restore said shaft to normalas soon as the motor has ceased to act. The motor drives a worm 3697(Fig. 4) which in turn rotates a worm- Wheel 3667 carrying an annularflange 3690. A shaft 3600 on which said wornrwheelis journaled carries adisk 3691 Within said flange. This disk is peripherally recessed toaccommodate struts 3631 for clutching the disk and flange together. Theshaft 3600 carries a driving cam 3668 operating upon a roll 3630(Fig. 1) at the lower end of a pitman 3691sjointed at its upper end to acrank arm 190 on the shaft I -radial side and in order to preventchattering of the clutch the following means are emloyed: Asnail-backcam 3611; is. secured to the shaft. 3600f. (Fig. 2) and an armor bar 3610i is pivotedto thejcasing andequipped arm of the segment3615*.

with a roll 3632-1; pressed against the periphery of said snail-back camby a spring 3685 which connects the arm or bar 3610i with the casing.The form and relative arrangement of these parts is such that as theabrupt face of the cam 3668 passes the roll 3630,

the roll 3632: crowds past the nose of thesnail-back cam and preventsanyback lash which the springs of the clutch might otherwise cause.These clutch springs operate to thrust the struts 3631 into drivingengagement with the disk 3691 and the flange 3690. A disk 3610 looseupon the shaft 3600 carries pins 3656 loosely engaging the open centersof the struts. Said disk 3610- carries a stop plate or strip 3617 andthere are journaled in the casing two plugs 3650 formed with inwardlyprojecting end portions 3650 semi-circular in cross-section forco-aetion as detents with the stop plate or strip 3617 (see' slotted toengage guiding pins 3656-}; and bifurcated to straddle studs at theouter ends of levers 3612 and3613. A spiral spring 3688 connects thesetwo levers so as to hold their outer ends normally elevated and thelever 3613 is bifurcated to engage a stud of the lever 3612 so as tosecure an even depression of the bar 3698. The lever 3612 is extendedrearwardly and equipped with a stud 3653 i engaging a slot in the upperend of a vertical bar 3627". The latter is connected by a spiral spring3682 with the rear.- Wardly extending arm of said lever 3612 and it willbe seen that depression of the bar 3698 will operate to elevate the bar3627 unless the latter is blocked, in which case the spring 3682 willstretch. The vertical bar is made in sections and the middle section3627? has a forward extension 36 19 and an intermediate upwardprojection 3627, the latter to prevent the rise of the bar when thehandle is in place or to prevent the insertion of the handle when thebar is elevated, and said forward extension 36 19 adapted to coeperatewith a stud 3649 on the sector 311 to effect full restoration of thevertical bar to depressed position shortly after the machine starts tooperate. The lowermost section 3651-}; of the vertical bar takes theform of a round rod which extends loosely through an eye 3651i securedto the 'It will be seen that through the connec- Thus the clutch isnormally re tions last described the elevation of the vertical barthrough depression of the finger bar 3698 will result in turning thedetent plugs and releasing the clutch. A spring 3684 surrounds therod-like portion of the section 36512- of the vertical bar and a thumbnut 3630-;- is applied to the lower end of said section /of the bar sothat the latter may be drawn downwardly at will should the machinehappen to stick with the projection 3627 across the shaft 300 and.necessity thus arise for applying the handle to said shaft;

None of the above-described devices constitute per se any part of thepresent invention though their arrangement and mode of operation comeinto consideration in connection with the present embodiment of theinvention. i Coming now to the features which characterize the latterthe lower one of the two detent plugs 3650 has secured to it arearwardly irojecting arm 3618 which must necessarily e depressed as anaccompaniment to elevation of the segment arm 3615 (Fig. 1). Anysuchmovement is normally prevented by the engagement with said arm 3618of the upper end of a lever 36 19 pivoted intermediate its ends to thecasing. The arm 3618 is preferably notched to receive the point or noseof the lever 3619 and the movements of the latter are limited by theabutment of suitable shoulders in its pivot portion with a pin 3635-projecting from the casing. A spiral spring 3687 normall presses thelever into engagement with the arm 3618 (Fig. 5). The lower arm of thislever carries an armature 3619 standing course attracts the armature andby overcoming the spring 3687 disengages the lever 3619 from the detentarm 3618. Thus effective manipulation of the starting bar 3698 dependsupon the energizing of this magnet. The latter occurrence does not ensueuntil the motor has attained full speed'after the current is turned on.The means for effecting this result will next be described.

The winding of the electromagnet is wired directly to binding posts 3895of the motor (Fig. 5) through suitable conductors A and A which bindingposts likewise take the line wires B and B .(Fig. 7). Within thesebinding posts are brushes in the form of copper tubes 3690 pressed bysprings 3880 into contact with disks 3812 and 38654; res pec-. tivelysecured to the armature shaft 3800 and insulated from each other. One ofthe line wires must of course traverse the field magnets before reachingthe binding )ost and its brush and in Fig. 7 the line wire is so reresented. The motor circuit is normally completed through a switch whichestablishes electrical connection between the disks 3812 and 38653;.This switch is of centrifugal character being adapted to automaticallyscopes piece normally seated in the flaring hollow of a block 3866secured against the side ot the disk 3865-;- but thoroughly insulatedthere from. The fastening screws 3866*? of said block make electricalconnection with the other disk 3812 being insulated from the disk l i3865; where they extend through the same.

The flaring of the hollow or socket of the block and the slight freeplay in the j oint of the lever provide for an efiectivecontact as willbe obvious. So long as this contact is preserved no current will flowthrough the magnet 3699 because such. contact supplies a ath of lessresistance for the curr it than that presented by the magnet winding andconnections. However, so soon as the motor attains a speed sufficient tobreak the contact by outward swing of the jointed lever against thestress of'the spring 3881 then the current must perforce traverse themagnet. This will result as before explained in unlocking the detentdevices so that the operator can release the clutch.

While the construction above described will be seen to thoroughly fulfilthe object primarily stated it .is to be understood that suchconstruction is susceptible oi? considerable modification withoutnecessarily departing from the spirit and scope of the invention.

What is claimed is:

1. In a machine of the character described, the combination with anelectric motor, driving connections including a normally-re strained.clutch, and manipulative means for releasing the clutch; of a lock forsaid means controlled by thespeed of the motor.

2. In a machine of the character described, the combination with anelectric motor, driving connections including a normally-re strainedclutch, and manipulative means for releasing the clutch; of a lock forsaid means centrifugally controlled by the speed of the motor. g

3. In a machine of the character described, the combination with anelectric motor, driving connections including a normally-restrainedclutch, and manipulative means for releasing the clutch; of an electriclock for said means controlled by the speed of the motor.

the combination with an electric motor, driving connections including anormally-restrained clutch, and manipulative means for releasing theclutch; of a lock for said means, an electro-inagnet controlling saidlock and wired to the motor brushes, and a speed-controlled switch inthe circuit of the motor beyond its brushes.

6. In a machine of the character-described, the combination with anelectric motor, driv ing connections including a normally-restrainedclutch and manipulative means for releasing the clutch; of a lock forsaid means an electro-rnagnet controlling said lock and wired to themotor brushes, and a centrifugal switch in the circuit of the motorbeyond its brushes.

7. In a machine of the character described, the combination with anelectric motor, driving connections including a normally-restrainedclutch, and manipulative means for releasing the clutch; of a lock forsaid means, an electro-magnet controlling said lock and wired to themotor brushes and a centrifugal switch carried by the armature of themotor,

8. In a machine of the character described, the combination with'anelectric motor, driv ing connections including a normally-restrainedclutch, and manipulative means for releasing the clutch comprising arocking detent; an electro-magnet wired to the m0- tor brushes, anarmature for said magnet spring-drawn into lockin en agement with saiddetent, and a centri uga switch inthe main circuit of the motor andcarried by the latters armature.

9. In a machine of the character described, the combination of fieldcoils, an armature shaft carrying insulated plates, a centrifugal switchconnecting said plates, brushes running in contact with the. latterrespectively, line wires connected with said brushes respectively," theone directly and the other through the field coils, anelectro-magnetwired directly to said brushes, an armature for saidmagnet, a spring-drawn lever carrying said armature, a detent normallyengaged by said lever,'-a clutch restrained by said detent, and drivingconnections con trolled by said clutch.

lo. In a machine of the character described, the combination with anelectric motor, driving connections including a clutch, and means forclosing theclutch; of a lock for said means controlled by the speed ofthe motor.

l1. ln a machine of the. character described, the combination with anelectric mo- ,for said means centrifugally controlled by the speed ofthe motor.

12. In machine of the character described, the cornbin ation with anelectric motor, driving connections including a clutch, and means forclosing the clutch; of an elec- &

trio loelt iforsaid means controlled by the speed of the motor.

' 139111 a machine of the character described, the combination with an'electric motor, driving connections including a clutch, and meansforclosing the clutchfof an elec tric lock: for said means centrifugallycontrolled by the speed of the motor.

14-. In; a machine of the charatcer described, the combination with anelectric m0:

tor, driv ing connections including a clutch,

and means for closing the clutch; of a lock for said means, anelectro-magnet controlling said lock and wired to the motor brushes,

and a speed-controlled switch in the circuit of the motor-beyond itsbrushes.

15. in a machine of the character described, the combination with anelectric mo tor, driving connections including a clutch and means forclosing the clutch; of a lock for said means, an electro-magnetcontrolling said lock and Wired to the motor brushes, and a centrifugalswitch in the circuit of the motor beyond its brushes.

16. In a machine of the character deof the motor.

ROY L. BURD. Vl itnessesz ALBERT E. LA SALLE. Enw. RAMsnY.

